Postgraduate Institute of Agriculture, University of Peradeniya, LK

C.K. Beneragama

Postgraduate Institute of Agriculture, University of Peradeniya, LK

About C.K.

Abstract

Sessile Joyweed (Alternanthera sessilis) locally known as Mukunuwenna is the most widely cultivated and consumed leafy vegetable in Sri Lanka. However, it loses its shelf life within 3 to 4 days after harvesting under ambient conditions, which is a big issue in the market and at the household level. Modified atmospheric (MA) packaging has given promising results for many perishables to increase their postharvest shelf life which has not been tested for Mukunuwenna. Hence, the present experiment was carried out to evaluate the effect of modified atmospheric packaging on keeping quality of Mukunuwenna. The experiment was conducted using perforated and nonperforated polyethylene with the gauge of 150 and 300. Mukunuwenna bundles with 100 g were used per each treatment. Irrespective of the gauge, perforated polyethylene (PPE) packages reduced water loss remarkably. However, PPE was not effective in delaying yellowing and leaf shedding. Sealed non-perforated polyethylene (SNPPE) packages reduced water loss and leaf yellowing remarkably irrespective of the thickness. SNPPE delayed chlorophyll degradation significantly (P<0.05) compared to that of PPE and control samples. Total soluble solid (TSS) content increased continuously in control samples whereas it was constant between 5.5% and 7% in other treatments. Leaf wilting and withering were the major problematic causes to lose the keeping quality of control treatment whereas leaf yellowing and decaying were the identified causes in PPE and SNPPE treatments under ambient conditions (34.2±1.8 °C). Visual quality rating (VQR) test results indicated the postharvest shelf life of control samples, PPE in both thicknesses and SNPPE in both thicknesses as 3, 4 and 6 days respectively. SNPPE with 150 and 300 gauges extend postharvest shelf life of Alternanthera sessilis (Mukunuwenna) by 100%.